Embodiments described herein relate generally to purge values, and, in particular, to purge valves for use in capacitors.
During operation, pressure buildup can occur within a housing of known energy storage devices, such as electrochemical double layer capacitors (EDLCs) and pseudocapacitors. Such pressure can result from, for example, ripple voltage or over voltage. Some known EDLCs and pseudocapacitors are fitted with a burst disk that opens and/or bursts when excessive pressure develops within the housing. For example, some known burst disks open when a pressure within the housing exceeds 100 psi. Known EDLCs and pseudocapacitors include burst disks as a safety measure to prevent the housing from rupturing due to excessive pressure.
Once a burst disk opens and/or bursts, exposure to the surrounding atmosphere can cause the EDLC or pseudocapacitor to rapidly deteriorate. Such deterioration reduces the effectiveness and the life of the energy storage device. As such, once the burst disk is opened, the EDLC or pseudocapacitor should be replaced as soon as possible.
Thus, a need exists for methods and apparatus related to a purge valve that releases pressure within a housing of an energy storage device when excessive pressure develops within the housing but prevents and/or minimizes the deterioration of the energy storage device due to exposure to the surrounding atmosphere.